<?php
/*
 *  $Id$
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\ORM\Query;

/**
 * Interface for walkers of DQL ASTs (abstract syntax trees).
 *
 * @author Roman Borschel <roman@code-factory.org>
 * @since 2.0
 */
interface TreeWalker {
	/**
	 * Initializes TreeWalker with important information about the ASTs to be walked
	 *
	 * @param Query $query The parsed Query.
	 * @param ParserResult $parserResult The result of the parsing process.
	 * @param array $queryComponents Query components (symbol table)
	 */
	public function __construct($query, $parserResult, array $queryComponents);
	
	/**
	 * Walks down a SelectStatement AST node, thereby generating the appropriate SQL.
	 *
	 * @return string The SQL.
	 */
	function walkSelectStatement(AST\SelectStatement $AST);
	
	/**
	 * Walks down a SelectClause AST node, thereby generating the appropriate SQL.
	 *
	 * @return string The SQL.
	 */
	function walkSelectClause($selectClause);
	
	/**
	 * Walks down a FromClause AST node, thereby generating the appropriate SQL.
	 *
	 * @return string The SQL.
	 */
	function walkFromClause($fromClause);
	
	/**
	 * Walks down a FunctionNode AST node, thereby generating the appropriate SQL.
	 *
	 * @return string The SQL.
	 */
	function walkFunction($function);
	
	/**
	 * Walks down an OrderByClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param OrderByClause
	 * @return string The SQL.
	 */
	function walkOrderByClause($orderByClause);
	
	/**
	 * Walks down an OrderByItem AST node, thereby generating the appropriate SQL.
	 *
	 * @param OrderByItem
	 * @return string The SQL.
	 */
	function walkOrderByItem($orderByItem);
	
	/**
	 * Walks down a HavingClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param HavingClause
	 * @return string The SQL.
	 */
	function walkHavingClause($havingClause);
	
	/**
	 * Walks down a JoinVariableDeclaration AST node and creates the corresponding SQL.
	 *
	 * @param JoinVariableDeclaration $joinVarDecl
	 * @return string The SQL.
	 */
	function walkJoinVariableDeclaration($joinVarDecl);
	
	/**
	 * Walks down a SelectExpression AST node and generates the corresponding SQL.
	 *
	 * @param SelectExpression $selectExpression
	 * @return string The SQL.
	 */
	function walkSelectExpression($selectExpression);
	
	/**
	 * Walks down a QuantifiedExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param QuantifiedExpression
	 * @return string The SQL.
	 */
	function walkQuantifiedExpression($qExpr);
	
	/**
	 * Walks down a Subselect AST node, thereby generating the appropriate SQL.
	 *
	 * @param Subselect
	 * @return string The SQL.
	 */
	function walkSubselect($subselect);
	
	/**
	 * Walks down a SubselectFromClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param SubselectFromClause
	 * @return string The SQL.
	 */
	function walkSubselectFromClause($subselectFromClause);
	
	/**
	 * Walks down a SimpleSelectClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param SimpleSelectClause
	 * @return string The SQL.
	 */
	function walkSimpleSelectClause($simpleSelectClause);
	
	/**
	 * Walks down a SimpleSelectExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param SimpleSelectExpression
	 * @return string The SQL.
	 */
	function walkSimpleSelectExpression($simpleSelectExpression);
	
	/**
	 * Walks down an AggregateExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param AggregateExpression
	 * @return string The SQL.
	 */
	function walkAggregateExpression($aggExpression);
	
	/**
	 * Walks down a GroupByClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param GroupByClause
	 * @return string The SQL.
	 */
	function walkGroupByClause($groupByClause);
	
	/**
	 * Walks down a GroupByItem AST node, thereby generating the appropriate SQL.
	 *
	 * @param GroupByItem
	 * @return string The SQL.
	 */
	function walkGroupByItem(AST\PathExpression $pathExpr);
	
	/**
	 * Walks down an UpdateStatement AST node, thereby generating the appropriate SQL.
	 *
	 * @param UpdateStatement
	 * @return string The SQL.
	 */
	function walkUpdateStatement(AST\UpdateStatement $AST);
	
	/**
	 * Walks down a DeleteStatement AST node, thereby generating the appropriate SQL.
	 *
	 * @param DeleteStatement
	 * @return string The SQL.
	 */
	function walkDeleteStatement(AST\DeleteStatement $AST);
	
	/**
	 * Walks down a DeleteClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param DeleteClause
	 * @return string The SQL.
	 */
	function walkDeleteClause(AST\DeleteClause $deleteClause);
	
	/**
	 * Walks down an UpdateClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param UpdateClause
	 * @return string The SQL.
	 */
	function walkUpdateClause($updateClause);
	
	/**
	 * Walks down an UpdateItem AST node, thereby generating the appropriate SQL.
	 *
	 * @param UpdateItem
	 * @return string The SQL.
	 */
	function walkUpdateItem($updateItem);
	
	/**
	 * Walks down a WhereClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param WhereClause
	 * @return string The SQL.
	 */
	function walkWhereClause($whereClause);
	
	/**
	 * Walks down a ConditionalExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param ConditionalExpression
	 * @return string The SQL.
	 */
	function walkConditionalExpression($condExpr);
	
	/**
	 * Walks down a ConditionalTerm AST node, thereby generating the appropriate SQL.
	 *
	 * @param ConditionalTerm
	 * @return string The SQL.
	 */
	function walkConditionalTerm($condTerm);
	
	/**
	 * Walks down a ConditionalFactor AST node, thereby generating the appropriate SQL.
	 *
	 * @param ConditionalFactor
	 * @return string The SQL.
	 */
	function walkConditionalFactor($factor);
	
	/**
	 * Walks down a ConditionalPrimary AST node, thereby generating the appropriate SQL.
	 *
	 * @param ConditionalPrimary
	 * @return string The SQL.
	 */
	function walkConditionalPrimary($primary);
	
	/**
	 * Walks down an ExistsExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param ExistsExpression
	 * @return string The SQL.
	 */
	function walkExistsExpression($existsExpr);
	
	/**
	 * Walks down a CollectionMemberExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param CollectionMemberExpression
	 * @return string The SQL.
	 */
	function walkCollectionMemberExpression($collMemberExpr);
	
	/**
	 * Walks down an EmptyCollectionComparisonExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param EmptyCollectionComparisonExpression
	 * @return string The SQL.
	 */
	function walkEmptyCollectionComparisonExpression($emptyCollCompExpr);
	
	/**
	 * Walks down a NullComparisonExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param NullComparisonExpression
	 * @return string The SQL.
	 */
	function walkNullComparisonExpression($nullCompExpr);
	
	/**
	 * Walks down an InExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param InExpression
	 * @return string The SQL.
	 */
	function walkInExpression($inExpr);
	
	/**
	 * Walks down an InstanceOfExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param InstanceOfExpression
	 * @return string The SQL.
	 */
	function walkInstanceOfExpression($instanceOfExpr);
	
	/**
	 * Walks down a literal that represents an AST node, thereby generating the appropriate SQL.
	 *
	 * @param mixed
	 * @return string The SQL.
	 */
	function walkLiteral($literal);
	
	/**
	 * Walks down a BetweenExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param BetweenExpression
	 * @return string The SQL.
	 */
	function walkBetweenExpression($betweenExpr);
	
	/**
	 * Walks down a LikeExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param LikeExpression
	 * @return string The SQL.
	 */
	function walkLikeExpression($likeExpr);
	
	/**
	 * Walks down a StateFieldPathExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param StateFieldPathExpression
	 * @return string The SQL.
	 */
	function walkStateFieldPathExpression($stateFieldPathExpression);
	
	/**
	 * Walks down a ComparisonExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param ComparisonExpression
	 * @return string The SQL.
	 */
	function walkComparisonExpression($compExpr);
	
	/**
	 * Walks down an InputParameter AST node, thereby generating the appropriate SQL.
	 *
	 * @param InputParameter
	 * @return string The SQL.
	 */
	function walkInputParameter($inputParam);
	
	/**
	 * Walks down an ArithmeticExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param ArithmeticExpression
	 * @return string The SQL.
	 */
	function walkArithmeticExpression($arithmeticExpr);
	
	/**
	 * Walks down an ArithmeticTerm AST node, thereby generating the appropriate SQL.
	 *
	 * @param mixed
	 * @return string The SQL.
	 */
	function walkArithmeticTerm($term);
	
	/**
	 * Walks down a StringPrimary that represents an AST node, thereby generating the appropriate SQL.
	 *
	 * @param mixed
	 * @return string The SQL.
	 */
	function walkStringPrimary($stringPrimary);
	
	/**
	 * Walks down an ArithmeticFactor that represents an AST node, thereby generating the appropriate SQL.
	 *
	 * @param mixed
	 * @return string The SQL.
	 */
	function walkArithmeticFactor($factor);
	
	/**
	 * Walks down an SimpleArithmeticExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param SimpleArithmeticExpression
	 * @return string The SQL.
	 */
	function walkSimpleArithmeticExpression($simpleArithmeticExpr);
	
	/**
	 * Walks down an PathExpression AST node, thereby generating the appropriate SQL.
	 *
	 * @param mixed
	 * @return string The SQL.
	 */
	function walkPathExpression($pathExpr);
	
	/**
	 * Gets an executor that can be used to execute the result of this walker.
	 *
	 * @return AbstractExecutor
	 */
	function getExecutor($AST);
}